银屑病皮损中细胞凋亡的原位标记检测与bcl-2的表达

目的　探讨细胞凋亡与银屑病发病的关系。方法　用末端脱氧核苷酰转移酶 (Td T)介导的 d- U TP-生物素缺口末端标记技术 (TUNEL ) ,原位检测了银屑病皮损的凋亡角朊细胞 ,应用免疫过氧化酶技术研究了正常人皮肤与银屑病皮损的 p5 3蛋白、增殖细胞核抗原 (PCNA)和 bcl- 2的表达。结果银屑病表皮各层中 ,大量角朊细胞呈现出细胞凋亡的形态学和生化特征。基底层及表皮中下部各层大量角朊细胞 PCNA染色强阳性 ,基底层中 bcl- 2阳性细胞明显减少。结论　在银屑病皮损中角朊细胞凋亡增加 ,推测可能是针对细胞过度增殖的一种稳态机理

Detection of Apoptosis by in Situ Labeling and Study on the Expression of bcl-2 in Lesions of Patients with Psoriasis

Objective To investigate the involvement of apoptosis in the lesions of patients with psoriasis. Methods The apoptosis was detected with terminal deoxynucleotidyl transferase mediated dUTP biotin nick end labeling (TUNEL), and the expression of p53, PCNA and apoptosis suppressing protein bcl 2 was assessed with immunoperoxidase technique in psoriatic lesions and normal skin. Results A large number of keratinocytes showing biochemical and morphologic features of cells undergoing apoptosis were observed in all the suprabasal layers of the psoriatic epidermis. The plaques from all patients analysed showed marked increase in the number of PCNA positive cells in the middle and basal keratinocytes, and a dramatic reduction in the number of bcl 2 positive cells in the basal cell layer. Conclusion The increased apoptosis of keratinocytes in the lesions of psoriasis might be a homeostatic mechanism to the hyperplasia of cells.